From the definition of an isosceles triangle as one in which two sides are equal, we proved the Base Angles Theorem - the angles between the equal sides and the base are congruent.Now we'll prove … [Read more...] about Converse Base Angle Theorem

# Isosceles Triangle

A triangle in which two of the sides are equal is called an “Isosceles triangle”, and we often identify the equal side by tagging them with a short line:

The third side is called the "base", and we will prove that the angels at the two sides of the base (and opposite the two equal sides) are congruent.

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*Now that we've explained the basic concept of isosceles triangles in geometry, let's scroll down to work on specific geometry problems relating to this topic.*

## Angle Bisector in a Triangle

This geometry problem presents an application of the angle bisector theorem in a triangle. It also incorporates several other concepts we've explored, like the properties of isosceles triangles and … [Read more...] about Angle Bisector in a Triangle

## Converse Angle Bisector Theorem for Isosceles Triangles

One of the properties of an isosceles triangle is that the height to the base bisects the apex angle.The converse of this is also true - If the bisector of an angle in a triangle is perpendicular … [Read more...] about Converse Angle Bisector Theorem for Isosceles Triangles

## Isosceles Triangles: the Median to the Base is Perpendicular to the Base

In a triangle, a line that connects one corner (or vertice) to the middle point of the opposite side is called a median. Another property of isosceles triangles, which is simple to prove using … [Read more...] about Isosceles Triangles: the Median to the Base is Perpendicular to the Base

## Isosceles Triangles: the Height to the Base Bisects the Apex Angle

We can use the proof that the height to the base bisects the base, and get a "two-for-one," as the exact same proof shows us multiple corresponding parts that are congruent.ProblemProve … [Read more...] about Isosceles Triangles: the Height to the Base Bisects the Apex Angle

## The Height to the Base of an Isosceles Triangle Bisects the Base

Having proven the Base Angles Theorem for isosceles triangles using triangle congruency, we know that in an isosceles triangle the legs are equal and the base angles are congruent.With these two … [Read more...] about The Height to the Base of an Isosceles Triangle Bisects the Base

## Base Angles Theorem

We will prove most of the properties of special triangles like isosceles triangles using triangle congruency because it is a useful tool for showing that two things - two angles or two sides - are … [Read more...] about Base Angles Theorem